Irrigation

Irrigation in Marion County is vital to maintaining its active and vibrant agricultural community. Irrigation is needed in the county during the summer months when rainfall is limited and crops are growing. Depending on the system and management used, there are maximum efficiencies that can be reached. An efficient irrigation water application system coupled with good water management can save property owners money by reducing energy costs and increasing the amount of land irrigated.

System and Management

The type of irrigation system and the quality of management defines the limits on application efficiency one can achieve. Irrigation management plays a large role in achieving high levels of irrigation efficiency. It is possible to install a high efficiency system and still have low application efficiencies due to improper management. Choose accordingly and be aware of the required labor and operational maintenance associated with that particular system. The three commonly used irrigation methods in Marion County are surface, sprinkler, micro and drip irrigation.

Key Factors of an Irrigation System

• Crop water requirement
• Application uniformity
• Water supply reliability
• Operational precision
• Water use efficiency
• Economic returns

Water Districts

There are two types of water districts: Irrigation and Water Control. A Water Control District has the ability to manage more than one resource, while an Irrigation District only delivers irrigation water.

Marion County currently has four user owned water districts that deliver water and maintain drainage in specific areas of the county.

• Sidney Irrigation Cooperative
• East Valley Water Control District
• Lake Labish Water Control District
• Santiam Water Control District

Water districts provide property owners within the district with the required infrastructure for obtaining water from the point of diversion to their property. Property owners are required to pay an annual fee for the use of the infrastructure. The Districts are required to maintain the ditches and other aspects of the system. Property owners are asked not to alter or change district irrigation ditches in any way. A water right is required to use the water from a canal or ditch that is adjacent to your property. Be aware that what appears to be a stream on your property might be an irrigation or drainage ditch.

Water Conservation via Irrigation Scheduling

Weather Based Monitoring : Monitor weather (temperature, rainfall, humidity, and crop evapo-transpiration) patterns to schedule irrigation application. Computer based programs and local weather stations should be used for scheduling.

Soil Based Monitoring : The available water holding capacity of a soil depends on soil texture and organic matter content. Monitoring the soil moisture during the growing season will help reduce water loss through over irrigating. Soil moisture monitoring can be done by the “feel and appearance” method or via more sophisticated methods.

Evaporation Based Monitoring : With a close growing crop, water evaporation from an open water source can approximate the evapo-transpiration (ET) rate of the crop. ET gauges, which operate on the same principle, are available to more precisely monitor evaporation for irrigation scheduling.